Nitinol prostheses for the treatment of inoperable malignant esophageal obstruction

Safe oesophageal stent deployment using a checklist system instead of fluoroscopy

BACKGROUND

Stenting is the management of choice for many benign and malignant oesophageal conditions and in the interest of safety stent insertion has traditionally been performed under fluoroscopic guidance. But this incurs additional expense, time, radiation risk and for the foreseeable future, an increased risk of Covid infection to patients and healthcare personnel. We describe a protocol that obviates the need for fluoroscopic guidance, relying instead on a systematic checklist to ensure safe positioning of the guidewire and the accurate positioning of the stent. The aim of this retrospective study was to review our experience of stent insertion employing a checklist system and compare our outcomes with outcomes using fluoroscopy in the literature.

METHODS

We performed a retrospective review of a prospectively collected dataset of all patients undergoing oesophageal stent insertion between December 2007 and October 2019. The primary end points were patient safety parameters and complications of stent insertion.

RESULTS

Total of 163 stents were deployed of which 93 (57%) were in males and the median age was 67.9 years (25-92 years). Partially covered self-expanding metallic stents (SEMS) were used in 80% of procedures (130/163). One hundred nineteen stents (73%) were for malignant strictures and 127 (78%) were deployed for strictures in the lower third of the oesophagus. There was no stent misplacement, injury, perforation or death associated with the procedure. Vomiting was the main post-operative complication (14%). Severe odynophagia necessitated stent removal in 3 patients. Stent migration occurred in 17 (10%) procedures with a mean time to stent migration of 6.4 weeks (range 1-20 weeks).

CONCLUSIONS

Oesophageal stent placement without fluoroscopy is safe provided that a strict checklist is adhered to. The outcomes are comparable to the results of fluoroscopic stent placement in the literature, with considerable saving in time, cost, personnel, and risks of radiation and Covid exposure.

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.

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

We evaluated the effectiveness of a double-layered polytetrafluoroethylene (PTFE)-covered nitinol stent in the palliative treatment of malignant esophageal strictures. A double-layered PTFE-covered nitinol stent was designed to reduce the propensity to migration of conventional covered stent. The stent consists of an inner PTFE-covered stent and an outer uncovered nitinol stent tube. With fluoroscopic guidance, the stent was placed in 32 consecutive patients with malignant esophageal strictures. During the follow-up period, the technical and clinical success rates, complications, and cumulative patient survival and stent patency were evaluated. Stent placement was technically successful in all patients, and no procedural complications occurred. After stent placement, the symptoms of 30 patients (94%) showed improvement. During the mean follow-up of 103 days (range, 9-348 days), 11 (34%) of 32 patients developed recurrent symptoms due to tumor overgrowth in five patients (16%), tumor ingrowth owing to detachment of the covering material (PTFE) apart from the stent wire in 3 (9%), mucosal hyperplasia in 2 (6%), and stent migration in 1 (3%). Ten of these 11 patients were treated by means of placing a second covered stent. Thirty patients died, 29 as a result of disease progression and 1 from aspiration pneumonia. The median survival period was 92 days. The median period of primary stent patency was 190 days. The double-layered PTFE-covered nitinol stent seems to be effective for the palliative treatment of malignant esophageal strictures. We believe that the double-layer configuration of this stent can contribute to decreasing the stent's migration rate.

Morbidity and mortality after self-expandable metallic stent placement in patients with progressive or recurrent esophageal cancer after chemoradiotherapy

BACKGROUND

Placemet of self-expandable metallic stents in patients with advance esophageal cancer improves dysphagia and occludes tracheoesophageal fistulas. However, the safety of self-expandable metallic stents for patients who have undergone chemoradiotherapy is controversial. This study evaluated the morbidity and modality after self-expandable metallic stent placement in patients with progressive or recurrent esophageal cancer after chemoradiotherapy.

METHODS

A total of 22 patients in whom self-expandable metallic stents were placed because of progressive or recurrent esophageal cancer after chemoradiotherapy were studied.

RESULTS

All 22 patients had dysphagia, and 13 had a tracheoesophageal fistula. After self-expandable metallic stent placement, the mean dysphagia grade improved from 3.5 to 0.9, and tracheoesophageal fistula was successfully managed in all cases. Seventeen patients had T4 stage disease, and among 8 of them with invasion to the aorta, 6 (75%) died of sudden massive hemorrhage. Median survival for these 6 patients was 31 days (range 13-63 days) compared with 67 days (range 4-262 days) for all patients after self-expandable metallic stent placement.

CONCLUSION

Self-expandable metallic stent placement improved dysphagia and was useful for treatment of tracheoesophageal fistula. However, for patients with T4 lesions that invade to the aorta, self-expandable metallic stent placement after chemoradiotherapy should be considered carefully.

Comparative study of self-expandable metallic stent and bypass surgery for inoperable esophageal cancer

We evaluated the effect of two different therapies for 23 patients with inoperable esophageal cancer, of whom 13 patients underwent placement of a metallic stent and 10 received bypass surgery. We newly defined the improved level of food intake and the effective rate based on the grade of the patient's status in order to evaluate objectively. Although the effect of stent placement was significantly better than that of bypass surgery, there were no significant differences in the improved level of food intake and the effective rate between the two groups. Four out of 10 patients in the bypass group had suture insufficiency, resulting in no oral intake and a fatal outcome. In addition, the ratio of survival period of ability to ingest orally and in-hospital mortality was significantly favorable in the stent group compared with the bypass group. In conclusion, stent placement should be the first choice for inoperable malignant stenosis or esophageal fistula.

Retrievable covered nitinol stents: experiences in 108 patients with malignant esophageal strictures

PURPOSE

The authors report their experience with three types of retrievable covered nitinol stents in patients with malignant esophageal strictures.

MATERIALS AND METHODS

Three types of retrievable covered nitinol stents were designed. Type A stents were placed in 45 patients, type B stents were placed in 29 patients, and type C stents were placed in 34 patients. The stents were removed with use of a stent retrieval set under fluoroscopic guidance when the stents caused complications. Stent patency, symptom relief, survival rate, and complications were analyzed relative to stent type and radiation therapy.

RESULTS

The timing of radiation and the stent type have significant effects on occurrence of complications such as stent migration and fistula formation (P =.002 and P = 0.029, respectively). Complications were significantly more frequent in patients with the type B stent than those with type A or type C stents (P =.008). Patients who underwent radiation therapy before stent placement or who underwent no radiation therapy experienced substantially less complications than those who underwent radiation therapy after stent placement (P =.005 and P <.001, respectively). The survival period was significantly longer in patients who underwent radiation therapy after stent placement than in the other groups (P =.034). Stents were removed from 15 patients (14%) 2 days to 16 weeks (mean, 4 weeks) after stent placement as a result of severe pain (n = 7), stent migration (n = 6), or stent deformity (n = 2). Stent removal was well tolerated in all patients.

CONCLUSION

Use of retrievable covered nitinol stents seems to be a safe and effective method of treatment in patients with malignant esophageal strictures. However, removal of the stents was needed in 14% of the patients because of complications. Patients who underwent radiation therapy after stent placement and those with the type B stent experienced more complications than other patients.

Placement of esophageal self-expanding metallic stents without fluoroscopy

BACKGROUND

Fluoroscopy is routinely used to guide the placement of self-expanding metallic stents for the palliative treatment of patients with esophageal malignancy. This is a description of a novel method of stent placement without fluoroscopy.

METHODS

This technique relies on a clear endoscopic view of the proximal radiopaque marker on the stent. This was achieved by the application of an external white marker at this level. A gastroscope was passed, allowing guidewire deployment and measurement of stricture length. The endoscope was reinserted and placed alongside the guidewire giving direct visualization of the proximal margin of the stricture. The stent delivery device was positioned, keeping the white mark visible proximal to the stricture, and the stent was deployed.

RESULTS

Thirty consecutive patients with inoperable esophageal malignancy underwent endoscopic placement of self-expanding metal stents. Deployment in satisfactory position without fluoroscopy was successful in 23 of 30 (77%); there were no complications.

CONCLUSIONS

The majority of esophageal stents can be accurately positioned without fluoroscopy.

A comparison of 3 types of covered metal stents for the palliation of patients with dysphagia caused by esophagogastric carcinoma: a prospective, randomized study

BACKGROUND

There are currently 3 types of covered metal stents available in Europe for palliation of patients with malignant dysphagia. Their relative merits have not been compared in a prospective, randomized study.

METHODS

One hundred consecutive patients with esophagogastric carcinoma were randomized to placement of an Ultraflex stent, a Flamingo Wallstent, or a Gianturco-Z stent. Malignant strictures of the esophagus were treated by insertion of a small-diameter stent (n = 71), whereas those involving the gastric cardia were treated with a large-diameter stent (n = 29).

RESULTS

At 4 weeks, dysphagia had improved in all patient groups (p < 0.001), but the degree of improvement did not differ among the 3 groups (p = 0.14). There were differences among the 3 stent types with respect to major complications (Ultraflex stent: 8/34 [24%], Flamingo Wallstent: 6/33 [18%], and Gianturco-Z stent: 12/33 [36%]), but these were not statistically significant (p = 0.23). Nine patients (26%) with an Ultraflex stent, 11 (33%) with a Flamingo Wallstent, and 8 (24%) with a Gianturco-Z stent had recurrent dysphagia (p = 0.73), mainly because of tumor overgrowth or stent migration; 12 of 13 episodes of migration involved small-diameter stents in the esophagus.

CONCLUSIONS

All 3 covered metal stents evaluated offer the same degree of palliation of patients with malignant dysphagia. Placement of Gianturco-Z stents was associated with more complications as compared with Ultraflex stents and Flamingo Wallstents. Although stent migration is reduced by increasing stent diameter, tumor overgrowth remains an intractable problem that requires a new approach.

Use of metallic stents and balloons in the esophagus and gastrointestinal tract

The majority of malignant and benign strictures in the esophagus and GI tract can be treated with use of minimally invasive alternatives to surgery such as balloon dilation or metallic stents. Virtually any obstructing lesion in the esophagus, stomach, duodenum, colon, and rectum can be treated with these methods with use of interventional radiologic or endoscopic techniques. In general, metallic stents are reserved for malignant strictures and balloon dilation is indicated for benign lesions. Patients with malignant esophageal fistulas and perforations can be palliated effectively and promptly by sealing the fistula or leak by deployment of a covered stent. Patients with malignant disease may benefit from a treatment regime that includes metallic stent placement, chemotherapy, radiation therapy and/or brachytherapy, although the efficacy of such combined therapies has yet to be defined. Further refinements to stent design are required. The ideal stent would be resistant to tumor ingrowth and migration. Placing a coating material on uncovered stents to prevent tumor ingrowth may achieve these aims. Finally, a biodegradable stent that dissolves before the development of intimal hyperplasia might enable stents to be used to treat benign strictures.

Covered retrievable expandable nitinol stents in patients with benign esophageal strictures: initial experience

PURPOSE

To investigate the safety and clinical effectiveness of covered retrievable expandable nitinol stents in 25 patients with a benign esophageal stricture.

MATERIALS AND METHODS

Under fluoroscopic guidance, covered retrievable expandable nitinol stents were placed in 25 patients with a benign esophageal stricture and were removed with a retrieval hook 1-8 weeks later.

RESULTS

Stent placement was successful in all patients, with no procedural complications. After stent placement, all patients could ingest solid food. The stents were successfully removed from all but two patients. One patient passed the stent via the rectum, and the other regurgitated a high cervical stent. After stent removal, one patient developed a small esophagobronchial fistula, which spontaneously sealed within 1 week of stent removal. After stent removal or migration, all patients could ingest solid food. During follow-up (mean, 13 months; range, 2-25 months) after stent removal or migration, 12 patients maintained their improvement in dysphagia and needed no further treatment. Thirteen patients with recurrence were treated by means of repeat balloon dilation.

CONCLUSION

Use of retrievable expandable nitinol stents seems to be a safe and effective method of treatment in selected patients with benign esophageal strictures.

Advances in gastrointestinal intervention: the treatment of gastroduodenal and colorectal obstructions with metallic stents

Metallic stents are currently an established component of the endoluminal treatment of stenoses within the blood vessels, bile ducts, esophagus, trachea, and bronchi. With the development of newer stent designs and delivery systems and the general momentum toward minimally invasive therapies, metallic stent placement has expanded into the nonsurgical therapy for gastroduodenal and colorectal obstructions. The use of metallic stents within the stomach, duodenum, or colon is intended not to be curative but to provide nonsurgical palliation for the symptoms of gastric or colonic obstruction. This palliation may be intended for the life of the patient in the case of unresectable disease or as a temporizing procedure prior to a definitive surgical procedure. In the latter clinical scenario, the benefits of a minimally invasive intestinal decompression procedure include (a) quick and noninvasive relief of the intestinal obstruction in an acutely ill patient that obviates a more extensive procedure; (b) allowance of time to improve a patient's overall medical condition and thus to allow a patient to better tolerate the definitive surgical procedure; and (c) reduction of the complexity of the definitive procedure by eliminating the need for staged procedures and allowing the definitive procedure to be performed at one setting.

A new design metal stent (Flamingo stent) for palliation of malignant dysphagia: a prospective study. The Rotterdam Esophageal Tumor Study Group

BACKGROUND

Metal stents are not superior to conventional endoprostheses with respect to the incidence of recurrent dysphagia because of tumor ingrowth with uncovered stents and migration with their covered counterparts. To overcome these limitations, a partially covered (inside-out covering) metal stent with a conical shape and a varying braiding angle of the mesh along its length, the Flamingo stent, has been developed.

METHODS

From March 1997 to October 1997, 40 consecutive patients with dysphagia due to malignant tumors had either a small diameter (proximal/distal diameter 24/16 mm; n = 21) or a large diameter Flamingo stent (proximal/distal diameter 30/20 mm; n = 19) placed.

RESULTS

There was statistically significant improvement in dysphagia, but improvement was not greater with large diameter stents compared to small diameter stents (p = 0.21). Major complications (bleeding [4], perforation [1], fever [1] and fistula [1]) occurred in 7 (18%) patients. Large diameter stents tended to be associated with more major complications than small diameter stents (5 vs. 2; p = 0.07). Pain following stent placement was observed in 9 (22%) patients and occurred more frequently in those who had prior radiation and/or chemotherapy (p = 0.02). Recurrent dysphagia (mainly due to tumor overgrowth) occurred in 10 (25%) patients.

CONCLUSIONS

Flamingo stents are effective for palliation of malignant dysphagia, but the large diameter stent seems to be associated with more complications involving the esophagus than the small diameter stent. Because recurrent dysphagia is mainly due to tumor progression, further technical developments in stent design are needed.

CT appearance of implanted esophageal stents

Three different types of esophageal stents, the Z-stent, Ultraflex, and Wall-stent, exhibit different shapes on CT, which may suggest a difference in the radial forces applied by each of the stents. CT is useful for displaying the relationship between an esophageal stent and adjacent structures and complications.

Interventional radiology and the use of metal stents in nonvascular clinical practice: a systematic overview

PURPOSE

The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use.

MATERIALS AND METHODS

Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English.

RESULTS

Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief.

CONCLUSION

Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.

The use of oesophageal, self-expanding, metal stents

Self-expanding metal stents have become increasingly popular in the effort to relieve the distressing symptoms associated with malignant oesophageal disruption. Despite numerous medical reports on the effectiveness of oesophageal stents, an extensive literature search revealed no nursing research on this subject. Through personal experience and reflection, the authors identified some distressing complications associated with oesophageal stenting. Their concerns resulted in a retrospective audit to assess the relief of dysphagia and identify any complications experienced by 37 patients who had received oesophageal stents. The results of this audit are inconsistent with previous medical studies, and question the effectiveness of these devices in the relief of symptoms associated with oesophageal disruption. In fact, the authors were perturbed by the number of complications identified after stenting, especially haematemesis, malaena and haemoptysis. The authors recognize that this subject requires a larger, multi-centre study. They have identified that a thorough nutritional assessment of patients with stents would be beneficial, and that education of both nursing staff and patients about these stents was a necessity.

Coated self-expanding metal stents versus latex prostheses for esophagogastric cancer with special reference to prior radiation and chemotherapy: a controlled, prospective study

BACKGROUND

Self-expanding metal stents seem to be safer than conventional prostheses for palliation of malignant esophagogastric obstruction. However, recurrent dysphagia caused by tumor ingrowth in uncoated types remains a problem. In addition, prior radiation and/or chemotherapy may entail an increased risk of complications.

METHODS

Seventy-five patients with an esophagogastric carcinoma were randomly assigned to placement of a latex prosthesis under general anesthesia or a coated, self-expanding metal stent under sedation. At entry, patients were stratified for location of the tumor in the esophagus or cardia and for prior radiation and/or chemotherapy.

RESULTS

Technical success and improvement in dysphagia score were similar in both groups. Major complications were more frequent with latex prostheses (47%) than with metal stents (16%) (odds ratio 4.07: 95% CI [1.35, 12.50], p = 0.014). Recurrent dysphagia was not different between latex prostheses (26%) and metal stents (24%). Hospital stay was longer, on average, after placement of latex prostheses than metal stents (6.3 +/- 5.2 versus 4.3 +/- 2.3 days; p = 0.043). Only prior radiation and/or chemotherapy increased the risk of specific device-related complications with respect to the esophagus (12 of 28 [43%] versus 8 of 47 [17%]; odds ratio 3.66: 95% CI [1.24, 10.82], p = 0.029).

CONCLUSIONS

Coated, self-expanding metal stents are associated with fewer complications and shorter hospital stay as compared with latex prostheses, and prior radiation and/or chemotherapy increases the risk of device-related complications with respect to the esophagus.

Treatment of esophageal obstruction with covered, self-expanding esophageal Wallstents

BACKGROUND

Conventional endoluminal plastic prostheses used for relieving esophageal obstruction allow variable palliation. Covered, expandable metal stents provide an 18-mm lumen to allow improved deglutition.

METHODS

From December 1994 to December 1995, 20 patients underwent placement of self-expanding, silicone-covered Wallstents (Schneider, Plymouth, MN) for esophageal obstruction. Fifteen patients had obstruction secondary to carcinoma and 5 patients had benign esophageal stricture. There were 13 men and 7 women, ranging in age from 54 to 94 years. All patients underwent esophageal dilation using a flexible gastroscope and Savary bougies. After dilation to 42F or 45F, placement of the stent was performed under fluoroscopic control.

RESULTS

Follow-up was complete in all patients, ranging from 4 weeks to 12 months. Technical success was achieved in all patients. There was one postoperative death (bronchoesophageal fistula) and one migration of the stent requiring removal (peptic stricture). The remaining stents were well tolerated, even in the cervical region (4 patients). All patients successfully intubated were able to eat well, including solid foods.

CONCLUSIONS

Covered, self-expanding esophageal Wallstents are technically simple and safe to insert and appear to provide durable, excellent palliation of esophageal obstruction due to either benign or malignant conditions. A larger patient population is required to make firm conclusions.