Double-layered PTFE-covered nitinol stents: experience in 32 patients with malignant esophageal strictures

Recurrent Benign Urethral Strictures Treated with Covered Retrievable Self-Expandable Metallic Stents: Long-Term Outcomes over an 18-Year Period

PURPOSE

To assess the long-term outcomes of covered retrievable self-expandable metallic stent (REMS) placement for recurrent benign urethral stricture and to compare the outcomes associated with 3 types of covered REMSs.

MATERIALS AND METHODS

A retrospective study was performed in 54 male patients in whom 114 REMSs were placed between November 1998 and December 2016. These included 26 polyurethane-covered REMSs in 13 patients (group A), 47 internally polytetrafluoroethylene (PTFE)-covered REMSs in 21 patients (group B), and 41 externally PTFE-covered REMSs in 20 patients (group C). The outcomes were analyzed and compared between the groups.

RESULTS

Overall clinical success was achieved in 14 of the 54 patients (24%) at 5-year follow-up (group A, 12%; group B, 19%; group C, 40%). The overall complication rate was 60.5%, and the complication rate was significantly higher in group B than in groups A or C (group A vs B, P = .018; group B vs C, P = .002). The median stent indwelling time and maintained patency period were 3.1 months and 108 months, respectively. In multivariate analysis, stent indwelling time was the only significant factor associated with maintained patency.

CONCLUSIONS

The long-term outcome of covered REMSs has not achieved the desired success rate for the standard treatment of recurrent urethral stricture. However, externally PTFE-covered REMSs showed a better long-term outcome than the other studied types.

Double-layered covered stent for the treatment of malignant oesophageal obstructions: Systematic review and meta-analysis

AIM

To investigate the efficacy of double-layered covered stent in the treatment of malignant oesophageal obstructions.

METHODS

A systematic review and meta-analysis was performed following the PRISMA process. PubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus and online content, were searched for studies reporting on the NiTi-S polyurethane-covered double oesophageal stent for the treatment of malignant dysphagia. Weighted pooled outcomes were synthesized with a random effects model to account for clinical heterogeneity. All studies reporting the outcome of palliative management of dysphagia due to histologically confirmed malignant oesophageal obstruction using double-layered covered nitinol stent were included. The level of statistical significance was set at α = 0.05.

RESULTS

Six clinical studies comprising 250 patients in total were identified. Pooled technical success of stent insertion was 97.2% (95%CI: 94.8%-98.9%; I² = 5.8%). Pooled complication rate was 27.6% (95%CI: 20.7%-35.2%; I² = 41.9%). Weighted improvement of dysphagia on a scale of 0-5 scoring system was -2.00 [95%CI: -2.29%-(-1.72%); I² = 87%]. Distal stent migration was documented in 10 out of the 250 cases examined. Pooled stent migration rate was 4.7% (95%CI: 2.5%-7.7%; I² = 0%). Finally, tumour overgrowth was reported in 34 out of the 250 cases with pooled rate of tumour overgrowth of 11.2% (95%CI: 3.7%-22.1%; I² = 82.2%). No funnel plot asymmetry to suggest publication bias (bias = 0.39, P = 0.78). In the sensitivity analysis all results were largely similar between the fixed and random effects models.

CONCLUSION

The double-layered nitinol stent provides immediate relief of malignant dysphagia with low rates of stent migration and tumour overgrowth

Self-expandable metal stents for malignant esophageal obstruction: a comparative study between extrinsic and intrinsic compression

Self-expandable metal stents (SEMSs) are effective for malignant esophageal obstruction, but usefulness of SEMSs in extrinsic lesions is yet to be elucidated. This study is aimed at evaluating the clinical usefulness of SEMSs in the extrinsic compression compared with intrinsic. A retrospective review was conducted for 105 patients (intrinsic, 85; extrinsic, 20) with malignant esophageal obstruction who underwent endoscopic SEMSs placement. Technical and clinical success rates were evaluated and clinical outcomes were compared between extrinsic and intrinsic group. Extrinsic group was mostly pulmonary origin. Overall technical and clinical success rate was 100% and 91%, respectively, without immediate complications. Extrinsic and intrinsic group did not differ significantly in clinical success rate. The median stent patency time was 131.3 ± 85.8 days in intrinsic group while that of extrinsic was 54.6 ± 45.1 due to shorter survival after stent insertion. The 4-, 8-, and 12-week patency rates were 90.5%, 78.8%, and 64.9% respectively in intrinsic group, while stents of extrinsic group remained patent until death. Uncovered, fully covered, and double-layered stent were used evenly and the types did not influence patency in both groups. In conclusion, esophageal SEMSs can safely and effectively be used for malignant extrinsic compression as well as intrinsic.

Comparative study of self-expanding metal stent and intraluminal radioactive stent for inoperable esophageal squamous cell carcinoma

BACKGROUND

We compared the effectiveness of self-expanding metal stent alone vs. radioactive stent embedded with 125I seeds implantation insertion in patients of inoperable esophageal squamous cell cancer combined with malignant esophageal stenosis.

METHODS

We studied two groups of patients with stenosis attribute to inoperable esophageal squamous cell carcinoma. Group A had placed self-expanding metal stent alone insertion; group B encountered radioactive stent embedded with 125I seeds. Patients were followed up by monthly home visits or telephone interview. Survival time was analyzed with Kaplan-Meier analysis. Log rank test was used to analyze factors of survival time for all significant differences.

RESULTS

There was no significant difference between the two groups of all baseline characteristics. There was no statistical difference in complications including massive hematemesis, pain more than 1 month, stent migration, and restenosis. Survival time and causes of death such as tumor metastasis, massive hemorrhage, non-tumor-related factors, and restenosis were comparable between the two groups (P>0.05). The medical costs were significantly less in group A than those in group B (P<0.01).

CONCLUSIONS

Radioactive stent embedded with (125)I seeds was not significant in improving survival rate, but showed to increase hospitalization costs compared to self-expandable metal stent alone in treating inoperable esophageal squamous cell carcinoma stricture.

The clinical research of the endoscopic sequential treatment for patients with intermediate-advanced esophageal cancer: a randomized clinical trial

We tried to find an ideal therapeutic regimen for patients with advanced esophageal cancer. Totally 240 patients with advanced esophageal cancer were randomly divided into experimental group (endoscopic sequential treatment, 126 cases) and control group (traditional treatment, 114 cases) with a 2-year follow-up period. The experimental group was randomly divided into three subgroups: group A: local chemotherapeutic drug injection with ordinary metal stent implantation; group B: local chemotherapeutic drug injection with iodine-125 particle implantation; and group C: radiofrequency (RF) therapy with ordinary metal stent group. The control group was also randomly divided into three subgroups: group D: local chemotherapeutic drug injection group; group E: RF therapy group; and group F: common metal stent implantation group. The survival rate, survival quality, adverse reactions, and complications were compared among these groups. A significant improvement of curative effect was found in the experimental group. Group A and B had higher survival rate and survival quality, and lower esophagotracheal fistula incidence and metastasis rate, compared with group C. There was no significant difference in survival rate between group A and group B, while the quality of life was higher in group B than in group A. While patients in group B had lower esophagotracheal fistula incidence and metastasis rate comparing with group A. Local chemotherapeutic drug injection combined with iodine-125 particle stent might be an effective sequential treatment to improve the life quality of advanced esophageal cancer patients.

Palliation of esophageal cancer with a double-layered covered nitinol stent: long-term outcomes and predictors of stent migration and patient survival

PURPOSE

To evaluate the long-term clinical outcomes and the negative predictors after the deployment of double-layered stents in malignant esophageal strictures.

METHODS

This is a single-center study of patients who received a double-layered covered stent for the palliation of dysphagia due to malignant esophageal strictures in a 3-year period. 56 patients fulfilled the inclusion criteria. The study's primary end points were technical success, dysphagia improvement, stent migration, and complication rates; secondary end points were the stent's primary patency and overall survival. Cox regression analysis was used to adjust for confounding variables and to identify predictors of survival outcomes.

RESULTS

Technical success was 95%. Median dysphagia score improved significantly after stenting (p < 0.0001). Stent migration rate was 7.1% and occurred exclusively in the group of patients who received chemoradiotherapy (p < 0.01). The median stent patency was 87 days (range 5-444 days). Dysphagia reoccurred in 39.3% and was successfully managed with restenting in 98.2%. The median survival was 127 days (range 15-1480 days). Chemoradiotherapy and baseline histology did not influence survival outcomes. Survival was adversely affected by metastases (p = 0.005) and poor oral intake (p = 0.048). Patient survival was improved by repeat stenting in case of tissue overgrowth (p = 0.06).

CONCLUSION

The device is safe and effective for the treatment of patients with dysphagia due to esophageal cancer. Migration rate is zero for patients who do not receive chemoradiotherapy. Reintervention when required is a positive survival predictor.

Clinical application of iodine-eluting stent in patients with advanced esophageal cancer

The aim of the present study was to compare the clinical effectiveness of an iodine-eluting stent with a conventional stent in patients with advanced esophageal cancer. Patients with malignant esophageal cancer were randomly assigned to receive a conventional stent (group A) or an iodine-eluting stent (group B). Following implantation, the relief from dysphagia, survival time, routine blood tests, thyroid function examination and complications were compared in the two groups. Groups A and B consisted of 36 and 31 patients, respectively. The mean value that the dysphagia score decreased by was significantly lower in group A (0.83) compared with group B (1.65). The median survival time was longer in group B compared with group A (P=0.0022). No significant differences were observed in the severe complications between the two groups (P=0.084). The iodine-eluting esophageal stent is a relatively safe, feasible and effective treatment for malignant esophageal strictures.

How to design the optimal self-expandable oesophageal metallic stents: 22 years of experience in 645 patients with malignant strictures

OBJECTIVES

To evaluate the clinical efficacy and safety of self-expandable metallic stent (SEMS) placement for malignant oesophageal strictures and their relationship with stent designs.

METHODS

Seven generations of SEMS were used to treat 645 consecutive patients with oesophageal strictures. Logistic regression models were constructed to identify predictive factors associated with complications.

RESULTS

Stent placement was technically successful in 641 of 645 patients (99.4%). The clinical success rate was 95.5%. There were 260 (40.3%) complications after stent placement. Due to complications, 68 stents were removed; 66 of 68 stents (97.1%) were removed successfully. Stainless steel (SS) stents (odds ratio [OR] 4.18; 95% confidence interval [CI] 2.10, 8.32) and radiation therapy (RT) before stent placement (OR 4.23; CI 2.02, 8.83) were significantly associated with severe pain. Flared ends (OR 9.63; CI 3.38, 27.43), stricture length <6 cm (OR 2.01; CI 1.13, 3.60), and a stent diameter <18 mm (OR 3.00; CI 1.32, 6.84) were predictive factors of stent migration. Polyurethane membranes were associated with more frequent tumour ingrowth than polytetrafluoroethylene (PTFE) membranes (P = 0.002).

CONCLUSIONS

Despite the relatively high complication rate, retrievable self-expandable PTFE-covered nitinol stents equipped with a head and a tail appeared to be an effective treatment for malignant oesophageal strictures.

Fluoroscopically guided dilation of esophageal strictures in patients with dystrophic epidermolysis bullosa: long-term results

OBJECTIVE

The purpose of this study was to investigate the immediate and long-term outcomes after fluoroscopically guided balloon dilation of esophageal strictures in a series of patients with dystrophic epidermolysis bullosa (DEB).

MATERIALS AND METHODS

Between 2005 and 2011, the medical records of all patients with DEB treated with fluoroscopically guided balloon dilation of esophageal strictures were included in the study and retrospectively analyzed. The indication for treatment was dysphagia attributed to at least one radiologically verified esophageal stricture. The primary endpoints of the study included procedural technical success, clinical improvement assessed with a 0-4 dysphagia score, and major complication rate. Secondary endpoints were patient survival and reintervention rates.

RESULTS

Nineteen consecutively registered patients with DEB (age range, 10-51 years; mean, 30 ± 12.2 years) and dysphagia due to esophageal strictures were treated with fluoroscopically guided balloon dilation. In total, 90 procedures and 121 dilations were performed to manage 28 lesions. Balloon diameter ranged from 8 to 18 mm. The mean follow-up time was 47.51 ± 16.64 months (range, 17-73 months). The technical success rate was 96.7% (87/90). There were no major complications. The mean reintervention rate was 1.19 dilations per patient per year, and the postprocedural dysphagia score (0.72 [95% CI, 0.56-0.87]) was significantly lower than baseline (2.50 [95% CI 2.35-2.65]) (p < 0.001).

CONCLUSION

Repeated fluoroscopically guided balloon dilation is safe and effective for the management of dysphagia caused by esophageal strictures in DEB. Use of this technique was associated with marked clinical improvement in dysphagia and satisfactory long-term reintervention rates with no major complications.

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.

Retrospective comparison of internally and externally covered retrievable stent placement for patients with benign urethral strictures caused by traumatic injury

OBJECTIVE

The purpose of this article is to compare the clinical effectiveness and complications of externally and internally covered stents for the treatment of benign urethral strictures.

MATERIALS AND METHODS

From July 2002 to June 2010, 59 retrievable self-expandable polytetrafluoroethylene-covered nitinol stents were placed in 33 men with benign urethral strictures. These included 34 internally covered stents placed in 18 patients (group I) and 25 externally covered stents in 15 patients (group E). Stents were routinely removed 4 months after placement from patients who experienced no complications. Complications, duration of stent placement, removal techniques, and maintained patency rates were compared in the two groups.

RESULTS

Twenty-eight complications (82.4%) occurred in 15 patients in group I, whereas 12 complications (48%) occurred in six patients in group E (p=0.005). Three (16.7%) patients in group I and nine (60%) in group E had their stents electively removed without complications (p=0.010). Stent migration was more frequent in group I (47.1%) than in group E (24.0%). No tissue ingrowth was detected in group E, whereas six cases of tissue ingrowth occurred in group I (p=0.034). The standard technique was used more frequently in group E (70.8%). The median stent indwelling period was significantly shorter in group I than in group E (51.5 vs 114 days; p=0.34).

CONCLUSION

Despite their relatively high complication rates, externally covered stents are more effective with fewer complications than internally covered stents in the treatment of benign urethral strictures.

Antimigration property of a newly designed covered metal stent for esophageal stricture: an in vivo animal study

BACKGROUND

Covered self-expandable metal stents (SEMSs) are associated with a higher migration rate than uncovered SEMSs.

OBJECTIVE

The antimigration property of a novel covered SEMS was investigated in a canine esophageal stricture model.

DESIGN

The new stent (80 mm in length, 20 or 24 mm in diameter) has multiple protuberances on its body that were designed to be separated from the inner silicone membrane so that they could be embedded into the mucosa after deployment. Twenty-two beagle dogs were subjected to circumferential EMR in the middle esophagus for stricture formation. After 2 weeks, conventional covered stents were inserted in a control group (n = 11), and the newly designed covered SEMSs were inserted in a study group (n = 11).

SETTING

Animal laboratory.

INTERVENTIONS

Circumferential EMR of the middle esophagus for stricture formation, followed by endoscopic placement of a conventional or newly designed stent.

MAIN OUTCOME MEASUREMENTS

Migration, complications, survival, and esophageal histopathology.

RESULTS

There was no significant difference in the diameter of the esophageal stricture between the control and study groups (10 mm vs 11 mm, P = .52). Within 3 days, all stents in the control group had migrated, whereas 6 had migrated in the study group (100% vs 55%, P = .035). There were no significant complications directly associated with stent insertion.

LIMITATIONS

Complications, survival, and esophageal histopathology could not be compared because all of the conventional stents migrated in the control group within 3 days.

CONCLUSIONS

The newly designed covered SEMS is more resistant to migration than the conventional covered SEMS.

Intraluminal radioactive stent compared with covered stent alone for the treatment of malignant esophageal stricture

OBJECTIVE

This study was designed to compare the clinical effectiveness of intraluminal radioactive stent loaded with iodine-125 seeds implantation versus covered stent alone insertion in patients with malignant esophageal stricture.

METHODS

We studied two groups of patients with malignant esophageal stricture. Group A comprised 28 patients (19 men and 9 women) who underwent intraluminal radioactive stent loaded with iodine-125 seeds implantation and were followed prospectively. Group B comprised 30 patients (18 men and 12 women) who had previously received covered stent alone insertion; these patients were evaluated retrospectively. There was no crossover between the two groups during follow-up. Informed consent was obtained from each patient, and our institutional review board approved the study. The dysphagia score, overall survival rates, complication rates, and reintervention rates were compared in the two groups.

RESULTS

There were no significant differences between the two groups in terms of baseline characteristics. Stent placement was technically successful and well tolerated in all patients. The dysphagia score was improved in both groups after stent placement. The median survival was significantly longer in group A than in group B: 11 versus 4.9 months, respectively (P < 0.001). The complications of chest pain, esophageal reflux, and stent migration was more frequent in group B, but this difference did not reach statistical significance. There was no statistical difference in reintervention between two groups.

CONCLUSIONS

Intraluminal radioactive stent loaded with iodine-125 seeds implantation was a feasible and practical management in treating malignant esophageal stricture and was superior to covered stent alone insertion, as measured by survival.

Evaluation of the Rebound Hernia Repair device for laparoscopic hernia repair

This investigation of the Rebound Hernia Repair Device found that the device has favorable handling characteristics and may serve as a useful agent in laparoscopic hernia repair.

Background:

The characteristics of the ideal type of mesh are still being debated. Mesh shrinkage and fixation have been associated with complications. Avoiding shrinkage and fixation would improve hernia recurrence rates and complications. To our knowledge, this is the first study of a device with a self-expanding frame for laparoscopic hernia repair.

Methods:

Six Rebound Hernia Repair Devices were placed laparoscopically in pigs. This device is a condensed polypropylene, super-thin, lightweight, macro-porous mesh with a self-expanding Nitinol frame. The devices were assessed for adhesions, shrinkage, and histological examination. Laboratory and radiologic evaluations were also performed.

Results:

The handling properties of the devices facilitated their laparoscopic placement. They were easily identified with simple x-rays. The mesh was firmly integrated within the surrounding tissue. One device was associated with 3 small adhesions. The other 5 HRDs had no adhesions. We noted no shrinkage or folding. All devices preserved their original size and shape.

Conclusions:

At this evaluation stage, we found that the Rebound Hernia Repair Device may serve for laparoscopic hernia repair and has favorable handling properties. It prevents folding and shrinkage of the mesh. It may eliminate the need for fixation, thus preventing chronic pain. The Nitinol frame also allowed radiologic evaluation for gross movement. Further studies will be needed to evaluate its clinical application.

Gastric Outlet Obstruction Palliation: A Novel Stent-Based Solution

Gastric outlet obstruction (GOO) after esophagectomy is a morbid outcome and significantly hinders quality of life for end-stage esophageal cancer patients. In the pre-stent era, palliation consisted of chemotherapy, radiation, tumor ablation, or stricture dilation. In the current era, palliative stenting has emerged as an additional tool; however, migration and tumor ingrowth are ongoing challenges. To mitigate these challenges, we developed a novel, hybrid, stent-based approach for the palliative management of GOO. We present a patient with esophageal cancer diagnosed with recurrent, metastatic disease 1 year after esophagectomy. She developed dehydration and intractable emesis, which significantly interfered with her quality of life. For palliation, we dilated the stenosis and proceeded with our stent-based solution. Using a combined endoscopic and fluoroscopic approach, we placed a 12-mm silicone salivary bypass tube across the pylorus, where it kinked slightly because of local tumor biology. To bridge this defect and ensure luminal patency, we placed a nitinol tracheobronchial stent through the silicone stent. Clinically, the patient had immediate relief from her pre-operative symptoms and was discharged home on a liquid diet. In conclusion, GOO and malignant dysphagia after esophagectomy are significant challenges for patients with end-stage disease. Palliative stenting is a viable option, but migration and tumor ingrowth are common complications. The hybrid approach presented here provides a unique solution to these potential pitfalls. The flared silicone tube minimized the chance of migration and impaired tumor ingrowth. The nitinol stent aided with patency and overcame the challenges of the soft tube. This novel strategy achieved palliation, describing another endoscopic option in the treatment of malignant GOO.

Clinical outcomes of using a conservative approach of late esophageal stent placement in palliation of malignant dysphagia

BACKGROUND

Esophageal stents have been used as first-line treatment for palliation of malignant dysphagia, but this is associated with significant complications. The present study evaluated clinical outcomes and survival in patients with malignant dysphagia with esophageal stent placement who did not respond to prior chemoradiation or endoscopic modalities.

PATIENTS AND METHODS

Patients with esophageal cancer, who had esophageal stents, were retrospectively reviewed from the electronic medical records. The patient demographics, type of stent placed, dysphagia scores, stent-related complications, and survival were recorded.

RESULTS

Thirty-five patients with esophageal cancer received a total of 41 stents. There were 25 males and 10 females with mean age of 69.8 years. Twenty-two patients had esophageal adenocarcinoma, ten patients had squamous cell carcinoma, and three had poorly differentiated tumor. Esophageal malignancy was early stage (I, II) in 10 patients and advanced (III, IV) in 24 patients. Three patients had upper esophageal involvement, eight patients had mid-esophageal involvement; distal esophageal malignancy was present in 24 patients with 10 patients having gastroesophageal junction involvement. Six patients presented with tracheoesophageal fistula. Nine patients had prior esophagectomy. Thirty-three patients had chemoradiation, and 32 patients had other endoscopic therapies previously. Twelve of the 35 (33%) patients developed stent-related complications; nine patients had dysphagia due to various causes; one patient each developed aspiration, intractable hiccups, and intractable vomiting after stent placement, respectively. Nine patients underwent a repeat esophagogastroduodenoscopy. Development of stent-related complications was not significantly associated with poor survival.

CONCLUSIONS

The clinical outcomes for patients with esophageal stent placement for malignant dysphagia after chemoradiation and other endoscopic treatments is not worse than that reported in patients where esophageal stent placement was used as first-line treatment.