nitinol and Tracheal-Neoplasms

Metallic airway stents are often used in the management of central airway malignancies. The presence of a metallic foreign body may affect radiation dose in tissue. We studied the effect of a metallic airway stent on radiation dose delivery in a phantom and an in vivo porcine model.. A metallic tracheal stent was fitted onto a support in a water phantom. Point dosimeters were positioned in the phantom around the support and the stent. Irradiation was then performed on a linear accelerator with and without the stent. Metallic tracheal stents were deployed in the trachea of three pigs. Dosimeters were implanted in the tissues near (Group 1) and away (Group 2) from the stent. The pigs were then irradiated, and the dose perturbation factor was calculated by comparing the actual dose detected by the dosimeters versus the planned dose.. The difference in the dose detected by the dosimeters and the planned dose ranged from 1.8% to 6.1% for the phantom with the stent and 0%-5.3% for the phantom without the stent. These values were largely within the manufacturer's specified error of 5%. No significant difference was observed in the dose perturbation factor for Group 1 and Group 2 dosimeters (0.836 ± 0.058 versus 0.877 ± 0.088, P = 0.220) in all the three pigs.. Metallic airway stents do not significantly affect radiation dose in the airway and surrounding tissues in a phantom and porcine model. Radiation treatment planning systems can account for the presence of the stent. External beam radiation can be delivered without concern for significant dose perturbation.

Topics: Alloys; Animals; Dose-Response Relationship, Radiation; Phantoms, Imaging; Radiation Dosage; Stents; Swine; Tracheal Neoplasms

Tracheal neoplasms account for less than 1% of all malignancies. In spite of their low incidence, these tumors represent potentially lethal phenomena. In cases of airway compromise and unresectable disease, the airway may be maintained by repeated bronchoscopic debulkings, and the use of CO(2) laser, silicone Montgomery T-tube and tracheal stents. The use of metallic expandable stents to relieve airway obstruction in advanced tracheal tumors was previously reported. Our aim was to evaluate the use of metallic expandable tracheal stents as a palliative relief from severe airway obstruction in cases of locally advanced, inoperable malignant tracheal tumors. Patients suffering from severe airway obstruction secondary to locally advanced tracheal tumors, who presented to the Otolaryngology Head and Neck Surgery and Chest Diseases Departments at the Main Alexandria University Hospital, Egypt, were included in this study. After endoscopic and radiological evaluation, expandable metallic tracheal stents (SENS; Ultraflex tracheal prosthesis; Boston Scientific Corp, Watertown, MA, USA) were inserted under general anesthesia to relieve airway obstruction. Postoperative follow-up with regard to improvement of respiration, tolerability of the stent and reporting of complications was done. Twelve patients were included, eight males and four females with a mean age of 61 years. Four patients (33.3%) had primary tracheal tumors and eight (66.7%) suffered from tumors infiltrating the trachea from nearby structures. The stent was easily inserted in all patients with no significant intraoperative complications. Postoperatively, the stent was well tolerated and all patients experienced good respiration with significant improvement of respiratory function test results. The most common complication reported was granulation tissue formation. Other complications were displacement of the stent, bad breath, re-growth of tumor tissue at the lower end of the stent and retention of secretions. We concluded that Ultraflex self-expandable stent is a good alternative for palliative relief from airway obstruction in cases of inoperable malignant tracheal tumors. Strict follow-up is mandatory for early detection and management of expected complications.

Topics: Adult; Aged; Airway Obstruction; Alloys; Female; Humans; Male; Middle Aged; Palliative Care; Stents; Tracheal Neoplasms; Tracheal Stenosis

Primary tracheal non-Hodgkin lymphoma is an extremely rare entity without consensus management strategy. We present a case of primary tracheal lymphoplasmacytoid lymphoma masquerading as asthma with wheezing and progressive dyspnea. A patented nitinol mesh stent was implanted in the right lateral cervical region 3 weeks before tumor resection. After 5.5-cm-long segmental tracheal resection, a neotracheal tube was constructed with cervical myocutaneous flap sandwiched around the implanted mesh stent, which was then anastomosed with the residual of the patient's trachea. The patient has been well for 30 months.

Topics: Adult; Alloys; Female; Humans; Lymphoma, B-Cell; Surgical Flaps; Surgical Mesh; Thoracic Surgical Procedures; Tracheal Neoplasms

A metallic stent for tracheobronchial stenosis provides a possible solution for poststenting complications such as sputum retention. We describe our experience with a novel anatomy-conforming metal stent placement at the carina.. A windowed stent was designed to match the tracheobronchial anatomy. The lateral window was used as a passage from the trachea to the contralateral main bronchus.. Six windowed stents were placed in 6 patients (mean age, 52.3 years). Two patients received an additional short straight stent placed in the contralateral bronchus, forming an overall Y stent at the carina. All patients had immediate relief from respiratory distress, and no sputum retention or stent migration occurred during the subsequent treatment period. Follow-up data showed that 4 patients are still alive. One patient died 2 months after stent placement of postradiation hemoptysis, and another died of metastasis 14 months after stent placement.. This anatomy-conforming metal stent has several advantages and its application in carinal stenosis is both effective and safe.

Topics: Adult; Alloys; Bronchial Diseases; Bronchoscopy; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Constriction, Pathologic; Dyspnea; Equipment Design; Female; Humans; Lung Neoplasms; Male; Middle Aged; Palliative Care; Respiratory Insufficiency; Stents; Tomography, X-Ray Computed; Tracheal Neoplasms; Tracheal Stenosis

Topics: Adult; Alloys; Bronchial Diseases; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Constriction, Pathologic; Equipment Design; Female; Humans; Lung Neoplasms; Male; Middle Aged; Palliative Care; Stents; Tracheal Neoplasms; Tracheal Stenosis

The purpose of this study was to evaluate the potential utility of implantation of a nickel-titanium alloy (nitinol) stent for the treatment of malignant or benign tracheobronchial stenosis.. We evaluated 18 patients (14 men and 4 women) who received 24 nitinol stents, between November 1997 and May 2000. All 18 patients had severe dyspnea caused by tracheobronchial stenosis. The underlying condition was malignant disease in 15 patients, and benign tracheal collapse in the other 3 patients.. Implantation of the stent was successfully performed in all patients. Seventeen patients experienced immediate clinical improvement in respiratory symptoms. The remaining 1 patient with a bronchial fistule after lobectomy did not benefit, and died of pneumonia at 16 days after the implantation. In 15 patients, the procedure was performed using a flexible bronchoscope under local anesthesia alone, while the remaining 3 patients needed intravenous sedation. There was no complication resulting from the stent implantation. Among the 3 patients with benign tracheal collapse, 2 patients were alive at 746 and at 401 days after the stent implantation, at the time of this report. One patient with cicatricial stenosis after intubation died of heart failure due to previous myocardial infarction. Among the 15 patients with malignant disease, 4 patients have survived for 177 to 305 days to date, while the other 11 patients have died of primary malignancy with a mean survival duration of 60.2 days.. The nitinol stent was effective in treating malignant or benign tracheobronchial stenosis, and had some remarkable advantages compared with other tracheobronchial stents. In stenting, most procedures can be performed using flexible bronchoscope under local anesthesia.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Anesthesia, Local; Bronchial Diseases; Bronchoscopy; Constriction, Pathologic; Female; Humans; Male; Middle Aged; Stents; Tracheal Neoplasms; Tracheal Stenosis

Recurrent tracheobronchial obstruction whether due to a benign or malignant cause is not always amenable to surgery and one is left with the dilemma of what to do for a patient who is slowly asphyxiating. Various modalities have been employed in the past with varying degrees of success. However due to the recent innovations in 'superelastic' biocompatible alloys we present our clinical experience with a new generation of metallic stents made from Nitinol. Over a 12-month period we inserted eight stents in six patients with malignant and benign tracheobronchial obstruction. Almost all patients had dramatic improvement in their symptoms and there was little airway reaction observed up to 18 months after insertion. However, one should exercise caution in inserting them for benign conditions as we regard them as permanent implants. Also evident is the inherent morbidity in this group of patients and this needs to be carefully considered prior to treatment.

Topics: Adult; Aged; Aged, 80 and over; Airway Obstruction; Alloys; Biocompatible Materials; Bronchial Neoplasms; Female; Humans; Male; Middle Aged; Otorhinolaryngologic Surgical Procedures; Stents; Tracheal Neoplasms; Treatment Outcome

To treat inoperable tracheal stenosis by using nitinol endotracheal stent and to solve some problems facing endotracheal stenting with other kinds of stents.. The stent was made of nitinol wire. It can be deformed to smaller size in iced water. With a self-made introducer, the stent was placed in the location of stenosis. After hot water was injected into the introducer, the stent resumed its original form and anchored there itself.. Altogether, 5 patients with severe tracheal stenosis received this treatment. Dyspnea was relieved immediately after implantation of stents in all patients. Long-term follow-up also showed satisfactory results.. Nitinol stent has some remarkable advantages as compared with other tracheal stents. It can be used as a new endoprosthesis in treating narrowed trachea.

Topics: Adult; Aged; Alloys; Carcinoma, Adenoid Cystic; Carcinoma, Squamous Cell; Female; Follow-Up Studies; Humans; Male; Middle Aged; Stents; Tracheal Neoplasms; Tracheal Stenosis