Implanted intrathecal drug delivery systems may malfunction as a result of fracture of the intrathecal catheter. A suspected catheter fracture not seen on plain radiographs of the catheter system will typically prompt a contrast-enhanced imaging study of the pump. Injection of iodinated contrast medium into the pump system with routine fluoroscopy can sometimes fail to reveal subtle leaks. The authors present a case demonstrating the utility of high-resolution, 3D-CT for intrathecal pump-catheter system interrogation when routine fluoroscopy is unrevealing. In this case, a catheter leak was suspected on the basis of the patient's history, but no obvious fracture was noted on plain radiographs. An intraoperative fluoroscopic study that included multiple injections of contrast medium into the catheter system failed to conclusively show a catheter leak. The authors therefore performed a post-injection 3D-CT study, which clearly demonstrated a leak from the intrathecal catheter just deep to the thoracolumbar fascia. The leak was visible on source images and was especially obvious after 3D reconstruction. This led to surgical revision of the catheter and subsequent resumption of normal pump function. The authors therefore suggest that if a leak is suspected in an implanted intrathecal catheter and routine contrast fluoroscopy is unrevealing, post-injection 3D-CT scanning should be performed to further investigate the possibility of a subtle leak.
Jason A. Ellis, Richard Leung and Christopher J. Winfree
Karim Mithani, Ying Meng, David Pinilla, Nova Thani, Kayee Tung, Richard Leung and Howard J. Ginsberg
A 52-year-old man with a 10-year history of treatment-resistant asthma presented with repeated exacerbations over the course of 10 months. His symptoms were not responsive to salbutamol or inhaled corticosteroid agents, and he developed avascular necrosis of his left hip as a result of prolonged steroid therapy. Physical examination and radiography revealed signs consistent with diffuse idiopathic skeletal hyperostosis (DISH), including a C7–T1 osteophyte causing severe tracheal compression. The patient underwent C6–T1 anterior discectomy and fusion, and the compressive osteophyte was removed, which completely resolved his “asthma.” Postoperative pulmonary function tests showed normalization of his FEV1/FVC ratio, and there was no airway reactivity on methacholine challenge. DISH is a systemic, noninflammatory condition characterized by ossification of spinal entheses, and it can present with respiratory disturbances due to airway compression by anterior cervical osteophytes. The authors present, to the best of their knowledge, the first documented case of asthma as a presentation of DISH.