Experience with Ultraflex expandable metallic stents in the management of endobronchial pathology

BACKGROUND: Experience with Ultraflex expandable metallic stents (Micro-invasive, Boston Scientific, Watertown, MA) in the management of endobronchial pathologies leading to airway compromise is reported. METHODS: Between January 1999 and August 2000, twenty-eight expandable metallic stents were inserted into 25 patients (7 men and 18 women; median age, 65 years) who presented with respiratory distress. Each patient had comorbid medical conditions or end-stage malignancy that precluded formal surgical repair. Seventeen patients had intrinsic airway obstruction, 5 had extrinsic compression, 2 had a tracheal tear, and 1 had a tracheoesophageal fistula. Stents were inserted through a bronchoscope under direct vision. Eighteen patients received tracheal stents alone (1 of these patients received two tracheal stents), and 5 patients received bronchial stents only. Two patients received a tracheal and a bronchial stent. Twenty-one stents were covered and seven were uncovered. RESULTS: All patients had successful stents with restoration of airway patency and closure of tracheal defects. One patient developed a respiratory infection early after the operation. Follow-up bronchoscopy confirmed satisfactory stent position in each patient. Late complications included sputum retention, halitosis, and granulation tissue formation. CONCLUSIONS: Ultraflex expandable metallic stents should be considered in the management of airway compromise in selected patients for whom formal surgical repair is inappropriate or contraindicated.     

Effect of the Palmaz balloon-expandable metallic stent in the trachea of pigs.

Endoscopically placed airway stents offer a viable option in primary or adjunctive treatment of severe pediatric tracheobronchial stenoses. Optimistic clinical reports substantiate the need for experimental studies to more effectively evaluate their clinical role. Development of an animal model comparable with the pediatric airway, amenable to endoscopic instrumentation, and capable of assessing effect on growth was the purpose of this pilot project. Nine 4-week-old piglets underwent endoscopic midtracheal placement of the balloon-expandable Palmaz metallic stent. Initial expansion and stent position were verified fluoroscopically and by direct videobronchoscopy. Serial endoscopic examination and stent reexpansion were performed 2 and 4 weeks after stent insertion. Animal weight, clinical tolerance, tracheal growth, and stent integrity were observed. Tracheal inflammation was evaluated grossly and by objective histopathologic criteria. Successful endotracheal stent placement and expansion were accomplished in all piglets. One pig died of anesthesia complications less than 24 hours after stent insertion. The remaining pigs exhibited excellent clinical tolerance through experiment completion. No detrimental effect on growth was noted, and effective dilatation of the stented tracheal region was observed. Stent incorporation was evident with significant mucosal ingrowth. Inflammation in the form of nonobstructing granulation tissue was present, and no evidence of necrosis or cartilage invasion was evident. The piglet trachea appears to be an excellent model for evaluation of expandable metallic airway stents in management of congenital and acquired tracheobronchial stenoses.     

The role of airway stents in the management of pediatric tracheal, carinal, and bronchial disease.

OBJECTIVE: A variety of stents are available to aid in the management of complex tracheal, carinal and bronchial stenoses. We reviewed our multi-institutional experience with airway stents in children. METHODS: Thirty-three children (age, 13 days-18 years) from four institutions have had a total of 40 stents placed to aid in the management of complex airway stenoses. Three stent types were utilized: 29 silastic stents, five expandable metal stents and six customized carinal stents (four patients had two stents and one patient had four stents). Thirty children had tracheal stents, six children had bronchial stents, and two infants had carinal stents (three children had stenting of more than one area and two had stenting of all three locations). Twenty-eight patients (age, 5 months-18 years; mean, 8.06 years; SEM, 1.13 years) had stents placed after a variety of airway reconstructive procedures. Four underwent stenting in a non-operative setting and one as preoperative stabilization. RESULTS: Twenty-seven patients survived. One patient died early due to bleeding. Five patients died late: two due to bleeding, one from mediastinitis, and two patients with functional airways died late from unrelated problems. Complications are related to stent type and location. Carinal stents can migrate; several techniques are available to help manage this problem. Wire stents are essentially non-removable requiring periodic dilation. Silastic stents stimulate granulation tissue formation requiring periodic bronchoscopic removal. CONCLUSION: Tracheal stenting can aid in the management of pediatric airway problems. Complications are common, but can be managed with appropriate intervention.     

A novel interventional therapy using the combination of bilateral bronchial stent dilatation and percutaneous cardiopulmonary support for critical airway obstruction due to metastatic carcinomatous carina.

For an inoperative critical airway obstruction (bilateral bronchial stenoses) from a carcinomatous carina due to the mediastinal lymphnodal metastasis from uterine cancer, we succeeded in improving the patient's severe dyspnea by the combination of bilateral bronchial stent dilatation and a percutaneous cardiopulmonary support (PCPS) system. The imminent airway stenosis with severe dyspnea may have a high risk of asphyxia and contact-flooding during implanting of the stent. By the novel use of PCPS in advance for blood-oxygenation as a respiratory support, we could safely perform the interventional therapy of bronchial expandable metallic stents, and the patient obtained a good quality of life without dyspnea until she died of systemic metastatic cachexia. This technique may possibly be approved as an option for temporary remission therapy of a critical airway obstruction.     

Double stenting for esophageal and tracheobronchial stenoses

Background. We examined the complications and outcomes of placing stents for both esophageal and tracheobronchial stenoses.

Methods. We placed stents for both esophageal and tracheobronchial stenoses in 8 patients (7 with esophageal cancer and 1 with lung cancer). Covered or noncovered metallic stents were used for the esophageal stenoses, except in 1 patient treated with a silicone stent. Silicone stents were used for the tracheobronchial stenoses. The grades of esophageal and tracheobronchial stenoses were scored.

Results. All patients experienced improvement of grades of both dysphagia and respiratory symptoms after stent therapy. The complications were: (1) 2 patients suffered respiratory distress after placement of the esophageal stent because of compression of the trachea by the stent; and (2) 3 patients developed new esophagotracheobronchial fistulae, and 2 patients had recurring fistula symptoms because of growth of preexisting fistulae after the stent placement, which were caused by pressure from the 2 stents. Despite the fistulae, the 5 patients treated with covered metallic stents did not complain of fistula symptoms, but 2 patients treated with noncovered metallic or silicone stents did complain.

Conclusions. For patients with both esophageal and tracheobronchial stenoses, a stent should be introduced into the tracheobronchus first. Because placement of stents in both the esophagus and tracheobronchus has a high risk of enlargement of the fistula, a covered metallic stent is preferable for esophageal cancer involving the tracheobronchus.     

Airway Stenting

Interventional pulmonology, otherwise known as airway stenting, has developed in the field of pulmonary medicine focused on using advanced bronchoscopic techniques to treat airway disorders. Tracheobronchial disorders can be caused by malignant or benign tumors, extrinsic compression, postintubation tracheal injuries, tracheobronchomalacia, or sequelae after tracheostomy. Tracheobronchial prostheses, known as airway stents, are used to palliate the effects of large airway obstruction. Specially designed stents are being used increasingly, not only in the airways, but also in the biliary tree, esophagus, urinary tract, and vascular system. There are two main types of airway stents currently available; tube stents made of silicone, and expandable metallic stents. Silicone stents are usually placed with the aid of a rigid bronchoscope while the patient is under general anesthesia. Unlike silicone stents, metal stents can be placed with a flexible bronchoscope. We examine the advantages and disadvantages of currently available stents and present our thoughts on the future development of airway stenting.     

Palliation of anastomotic obstructions in recurrent gastric carcinoma with the use of covered metallic stents: clinical results in 25 patients

BACKGROUND: The purpose of this study was to investigate the technical feasibility and the clinical effectiveness of the placement of covered self-expandable metallic stents for the treatment of anastomotic obstructions in recurrent gastric carcinoma. METHODS: With fluoroscopic guidance, covered stents were placed in 25 patients with recurrent gastric carcinoma for the palliation of obstructions at anastomotic sites (14 gastrojejunostomy, 11 esophagojejunostomy). All patients had severe nausea and recurrent vomiting before the stent placement. RESULTS: Stent placement was technically successful in 24 patients (96%). After stent placement, symptoms improved in all 24 patients. During the follow-up of 2 to 65 weeks (mean, 13.7 weeks), stent migration occurred in 1 patient 16 days after the procedure. He needed percutaneous catheter drainage because of an abscess, which was followed by esophagojejunostomy site rupture during a second stent trial. Stricture recurred in 4 patients because of tumor overgrowth 10 to 55 weeks after the procedure; all patients underwent coaxial placement of a second stent and had good oral intake. CONCLUSIONS: The placement of covered expandable metallic stents seems to be both technically feasible and an effective means for the palliation of anastomotic obstructions in recurrent gastric carcinoma. This procedure can be considered to be the primary choice for the palliation in those patients.     

Self-expanding tracheobronchial stents using flexible bronchoscopy

Endoscopic insertion of tracheobronchial stents is indicated to achieve patency of the airway in case of malignant or benign obstructing lesions. Until now, the placement of prostheses has required a rigid bronchoscope with specially designed insertion instruments. Self-expanding stents are currently used to treat stenoses of different hollow organs (vessels, urinary tract, gastrointestinal tract, bile duct, respiratory tract). We report the first case of a self-expanding stent implanted in the trachea and right main stem bronchus using flexible videobronchoscope under local anesthesia. The procedure was easy, safe, effective, and well tolerated. No complications occurred.     

Role of endoscopic endoprostheses in proximal malignant biliary obstruction

The management of hilar strictures is dependent upon their resectability and may therefore require a multidisciplinary approach. However, resectability rates for such tumors are reported to be in the region of 15%–20%, and, therefore, palliative therapy will be the mainstay of treatment for most patients. With the presenting symptoms being those of obstructive jaundice and the consequences of cholestasis, a significant improvement in morbidity can be obtained by achieving biliary drainage. A number of options are available, including the placement of Teflon or expandable metallic endoprostheses by either the endoscopic or percutaneous route. Some considerable debate exists as to which route of stent placement is best, and in many circumstances the decision will depend on the availability of local services. Some have suggested that success rates with percutaneous stenting are superior to those for endoscopic placement, but the latter technique may be associated with fewer complications. In competent hands, endoscopic placement does achieve a high rate of success and it should be remembered that a combined approach may further improve success rates. The debate over the use of plastic versus metallic stents is centered around the higher rates of stent occlusion/migration for plastic stents seen in some studies, although a stent change is usually possible. An additional advantage of metallic stents is that they may provide drainage of the side branches of the biliary tree through the mesh. However, possible drawbacks may be a greater difficulty in placement of a second stent where a first provides inadequate drainage, and cost issues often have to be taken into consideration. Considerable debate exists over the optimum number of stents required to achieve adequate drainage and minimize the risks of cholangitis. There is good evidence that if overfilling of the biliary tree with contrast is avoided with only the segments to be drained visualized, a single stent may be all that is required, while others argue that placement of more than one stent may improve survival. In the following review we discuss these issues, and conclude by considering success rates and complications following endoprosthesis insertion; we also discuss the prognosis of patients treated in this way. Received: September 5, 2000 / Accepted: October 26, 2000     

Medium-term follow-up after deployment of ultraflex expandable metallic stents to manage endobronchial pathology

Background

Between March 1997 and March 2004 we deployed 80 Ultraflex metallic expandable stents (Boston Scientific, Waterson, MA) in 69 patients under direct vision using rigid bronchoscopy. We report our medium- to long-term experience in patients for whom these stents were deployed.

Methods

To date 15 patients have been followed for more than 1 year (median 41 months, range 12 to 83 months) after stent deployment. Indications for stenting in these patients were neoplasia (5), stricture (5), airway malacia (1), iatrogenic tracheal tear (1), and compression from an aortic aneurysm (1), a right interrupted aortic arch (1), and a right brachiocephalic artery aneurysm with tracheomalacia (1). Ten tracheal stents (9 covered, 1 uncovered) and 10 bronchial stents (8 uncovered, 2 covered) were inserted, and 5 patients received two stents.

Results

Five of these patients experienced no long-term problems. Complications included troublesome halitosis (5), which was difficult to treat despite various antibiotic regimes; granulation tissue formation above and below the stent that was successfully treated with low-power Nd:YAG laser therapy (7); and metal fatigue (1). We did not encounter stent migration.

Conclusions

We conclude that Ultraflex expandable metallic stents have an important role in the management of selected patients with diverse endobronchial pathologies and are well tolerated in the long-term. Although associated granulation tissue can be successfully treated with Nd:YAG laser, halitosis can be a difficult problem to address.     

Covered expandable tracheal stents in the management of benign tracheal granulation tissue formation

BACKGROUND: Tracheal obstruction secondary to benign proliferation of granulation tissue is a difficult problem to address if tracheal resection is contraindicated. Some patients may benefit from Nd:YAG (neodymium: yttritium-aluminum garnet) laser fulguration or tracheal stenting. If uncovered expandable metallic stents are employed granulation tissue can regrow and proliferate through the mesh, thereby obstructing the lumen once again. Covered metallic stents confer the advantage of preventing granulation tissue proliferation and therefore maintain patency of the tracheal lumen. METHODS: Two patients who developed tracheal obstruction secondary to proliferating granulation tissue formation after tracheostomy and who were medically unfit for prolonged general anesthesia were successfully treated using covered expandable metallic tracheal stents. RESULTS: Each patient demonstrated a significant improvement in respiratory status, and in both patients, at 6 and 9 months' follow-up, stent position has not changed, tracheal lumen remains patent, and there has been no proliferation of granulation tissue through the stent. CONCLUSIONS: Covered expandable metallic stents should be considered in the management of patients with proliferating tracheal granulation tissue when tracheal resection is contraindicated.     

Complications of metallic stents in the pediatric airway.

OBJECTIVE: Our aim was to present our experience with complications caused by placement of metallic stents in the pediatric airway. DESIGN AND SETTING: We conducted a retrospective study of the medical records of patients with complications resulting from metallic stent placement, managed by the senior authors between 1993 and 2002. RESULTS: Nine children had complications associated with the placement of metallic airway stents. Of these, 8 children required stent removal. Granulation tissue and tracheal stenosis were seen in all 7 children with long standing stent placement. There was 1 stent death in this series. CONCLUSIONS: Metallic airway stents can cause significant complications in the pediatric airway. These complications may supersede the airway compromise that necessitated their initial placement. As such, metallic stent placement should be approached with caution. The likelihood and severity of complications increase with time, as do the difficulties encountered upon removal. The proportion of patients in whom metallic stents may be placed "permanently" without complications is not known. Therefore we recommend that metallic airway stents be considered a temporizing measure of limited duration.     

Biliary stenting for hepatobiliary-pancreatic disease

Since 1990, expandable metallic stents (EMS) have been used in biliary obstruction, which are thinner than the plastic endoprosthesis and can secure sufficient biliary tract. EMS treatment improves the prognosis of patients with unresectable malignant biliary obstruction. Several types of stent are available, and each has its own characteristics of expansion, flexibility, visibility, shorting, and size variation. Those characteristics must be taken into account when selecting a stent for individual patients. In the case of hepatic hilar obstruction, more than one EMS is needed and the position of stent placement is important. For bile duct cancer, stents should be placed in a side-by-side or end-to-side position, because in these cases the tumor affects in-growth through the stent, so repeat biliary drainage and stenting would be needed. EMS treatment is sometimes used for stenosis of the portal vein, but stent placement is not effective for chronic stenosis with collateral circulation. With the development of stenting instruments, biliary endoprosthesis has become safer and easier. But we must not forget that stent treatment is a palliative treatment and consider the indications for and selection of the stent carefully.     

Penetration to the aortic wall by a metallic airway stent. A successfully treated case with left pneumonectomy and aortic repair

Metallic airway stents were used widely at the beginning of airway stent use, but an accumulation of cases has revealed complications due to their use. A patient who received a Gianturco Z stent for bronchial tuberculosis suffered massive haemoptysis due to stent migration into the aortic wall. Left pneumonectomy with aortic repair was successfully performed. We suggest that metallic stents should not be used for benign airway palliation, as they may later cause life-threatening complications.     

Postoperative airway stenosis and stent therapy in carinal reconstruction for lung cancer

A 48-year-old male had adenocarcinoma of the right upper lung lobe that invaded the lower trachea. The right upper lobe, the carina, and 5 rings of the lower trachea were resected. The carina was reconstructed using end-to-end anastomosis between the trachea and right intermediate bronchus, with the left main bronchus anastomosed to the side wall of the intermediate bronchus. Two months after surgery, the right intermediate bronchus developed bronchomalacia and the tracheal anastomosis granulatory stenosis. Bronchomalacia was treated with 2 expandable metallic stents, and granulatory stenosis with a Dumon stent. Although the silicone stent successfully dilated the granulatory stenosis, the metallic stents caused delayed glanulatory stenosis. We concluded that a metallic stent is not desirable for treating postreconstructive airway stenosis including bronchomalacia, whereas a Dumon stent may be effective.     

Postoperative airway stenosis and stent therapy in carinal reconstruction for lung cancer.

A 48-year-old male had adenocarcinoma of the right upper lung lobe that invaded the lower trachea. The right upper lobe, the carina, and 5 rings of the lower trachea were resected. The carina was reconstructed using end-to-end anastomosis between the trachea and right intermediate bronchus, with the left main bronchus anastomosed to the side wall of the intermediate bronchus. Two months after surgery, the right intermediate bronchus developed bronchomalacia and the tracheal anastomosis granulatory stenosis. Bronchomalacia was treated with 2 expandable metallic stents, and granulatory stenosis with a Dumon stent. Although the silicone stent successfully dilated the granulatory stenosis, the metallic stents caused delayed glanulatory stenosis. We concluded that a metallic stent is not desirable for treating postreconstructive airway stenosis including bronchomalacia, whereas a Dumon stent may be effective.     

Candida infection in a stent inserted for tracheal stenosis after heart lung transplantation

Although there are many reports on the use of expandable metallic stents for treating an airway stenosis that develops after heart lung transplantation, complications from using these stents are rarely reported. We experienced a case of Candida infection in a stent that was placed to treat a tracheal stenosis after heart lung transplantation in an 11-year-old girl. The patient had progressive shortness of breath developed from the 5th postoperative week. Chest computed tomography and bronchoscopy revealed a stenosis at the level of the anastomosis. After repeated unsuccessful trials of endoscopic ablation of the granuloma, a Palmaz metallic expandable stent (8 × 30 mm) (Johnson and Johnson Interventional Systems Co, Warren, NJ) was placed, which was followed by immediate relief of the dyspnea. Bronchoscopy conducted immediately after the stent placement showed a free floating distal stent end, which needed to be followed up. The patient had been doing well for the next 9 months after stent placement when she again had shortness of breath develop. Endoscopic examination revealed an intraluminally growing fungal mass, which was particularly severe at the distal free edge of the stent. The culture yielded Candida albicans. Aggressive antifungal agents and surgical removal of the stent were planned, but the patient died 1 day after admission.     

可膨式金属胆道支架解除恶性胆管梗阻的临床应用及其疗效分析

目的 探讨可膨式金属胆道支架支解除恶性胆管梗阻的中远期疗效及初步分析影响疗效的因素,方法 １３４例各类恶性肿瘤导致胆管梗阻的患者接受金属支架放置术,其中内镜下经乳头放置１２８例,经皮经肝放置６例,随访引流效果并与同期９７例内镜下放置塑料支架的患者进行对比。结果 操作成功率９５．７％,并发症６．４％,黄疸消除率８５．６％,金属支架的平均通畅期为３００天,明显高于塑料支轲的８０天（Ｐ〈０．０１）;平均     

Endobronchial stenting as a palliation for advanced esophageal cancer

Three cases of airway invasion of esophageal cancer treated palliatively by endobronchial stenting are reported. In case 1 (a 60-year-old male) expandable metallic stents were inserted into the totally occluded left main bronchus. In case 2 (a 45-year-old male) a Dumon stent was inserted into the totally occluded left main bronchus. Both patients recovered from performance status 4 to performance status 1 or 0 and were in good condition before they died of cancer, 150 and 54 days after stenting in cases 1 and 2, respectively. In case 3, a Dumon stent was inserted into the left main bronchus before total occlusion. The patient recovered from performance status 3 or 2 to performance status 1 or 0 and survived 40 days after stenting with no signs of airway obstruction. Endobronchial stenting is a useful palliation for keeping the performance status at a good level in patients with esophageal cancer obstructing or narrowing the main airway.     

Endoscopic palliative treatment of the common bile duct at the hepatic hilum. Results in 583 patients treated in a single center over a 10-year period

BACKGROUND: The outcomes of endoscopic biliary drainage for malignant stenoses at the hepatic hilum were retrospectively evaluated. METHODS: From January 1990 to June 2001, 583 patients, 368 males, average age 69+/-18.5 years, were recruited. Endoscopic procedure consisted of insertion of 1 ore multiple stents, plastic or metallic, across the stricture, under mild sedation. RESULTS: Successful stent insertion was achieved in 518/583 (88.8%) patients and successful drainage in 474 (81.3%) patients. Early complications were observed in 101 (17.3%) patients with related-mortality of 17 (2.9%) patients. Late complications occurred in 39.9% of patients. Survival was of 189 days, on average. CONCLUSIONS: Endoscopic palliation should be the initial management of choice for malignant biliary stenoses at the hepatic hilum.