Elastic deformation properties of implanted endobronchial wire stents in benign and malignant bronchial disease : A radiographic in vivo evaluation

• Published in: Cardiovascular and interventional radiology 1999-03, Vol.22 (2), p.103-108
• Main Authors: HAUTMANN, H, RIEGER, J, HUBER, R. M, PFEIFER, K. J
• Format: Article
• Language: English
• Subjects: Airway Obstruction - diagnostic imaging; Airway Obstruction - etiology; Airway Obstruction - therapy; Balloon treatment; Benign; Biological and medical sciences; Bronchial Diseases - complications; Bronchial Diseases - diagnostic imaging; Bronchial Diseases - therapy; Bronchial Neoplasms - complications; Bronchial Neoplasms - diagnostic imaging; Bronchial Neoplasms - therapy; Carcinoma, Squamous Cell - complications; Carcinoma, Squamous Cell - diagnostic imaging; Carcinoma, Squamous Cell - therapy; Collapse; Compression; Cough; DEFORMATION; Diameters; Elastic deformation; Elastic properties; Elasticity; Equipment Design; EVALUATION; Evaluation Studies as Topic; FATIGUE; FLUOROSCOPY; Humans; Image Processing, Computer-Assisted; Implantation; Implants; IN VIVO; Intermetallic compounds; Mechanical properties; Medical sciences; NICKEL ALLOYS; Nickel titanides; PATIENTS; Pneumology; Prostheses; Prosthetics; RADIOLOGY AND NUCLEAR MEDICINE; Stents; Surgical implants; Tantalum; TITANIUM ALLOYS; Treatment Outcome; Tumors of the respiratory system and mediastinum; VASCULAR DISEASES; Wire; WIRES
• ISSN: 0174-1551; 1432-086X
• DOI: 10.1007/s002709900343

To evaluate the long-term mechanical behavior in vivo of expandable endobronchial wire stents, we imaged three different prostheses in the treatment of tracheobronchial disease. Six patients with bronchial stenoses (three benign, three malignant) underwent insertion of metallic stents. Two self-expandable Wallstents, two balloon-expandable tantalum Strecker stents and two self-expandable nitinol Accuflex stents were used. Measurements of deformation properties were performed during voluntary cough by means of fluoroscopy, at 1 month and 7-10 months after implantation. The procedures were videotaped, their images digitized and the narrowing of stent diameters calculated at intervals of 20 msec. After stent implantation all patients improved with respect to ventilatory function. Radial stent narrowing during cough reached 53% (Wallstent), 59% (tantalum Strecker stent), and 52% (nitinol Accuflex stent) of the relaxed post-implantation diameter. Stent compression was more marked in benign compared with malignant stenoses. In the long term permanent deformation occurred with the tantalum Strecker stents; the other stents were unchanged. Endobronchial wire stents can be helpful in the treatment of major airway collapse and obstructing bronchial lesions. However, evidence of material fatigue as a possible effect of exposure to recurrent mechanical stress on the flexible mesh tube may limit their long-term use. This seems to be predominantly important in benign bronchial collapse.