BACKGROUND: Nusinersen, the only treatment approved by the United States Food and Drug Administration for spinal muscular atrophy (SMA), is delivered intrathecally. This approach of drug administration presents challenges in SMA patients who have undergone spinal surgery for rod placement or fusion. Most of SMA2 patients have had spinal surgery by adolescence as standard of care for scoliosis. A posterior interlaminar approach to lumber puncture is often not possible in these patients, many of whom have completely fused spines.
PURPOSE: Previous studies have described the use of cone beam CT to access the spinal canal via the transforaminal route, however we have found the transforaminal route suboptimal using coned beam CT because of metallic artifact. Transforaminal fluoroscopic guidance for intrathecal administration of nusinersen has to our knowledge not yet been reported .
The study will describe the early results of technical success, complications of fluoroscopic guided intrathecal administration of nusinersen, and radiation dose.
MATERIALS AND METHODS: A retrospective review of 7 Nusinersen injections performed in SMA patients with spinal fusion. Transforaminal thecal access was obtained employing fluoroscopy alone. We analyzed results including technical success, complications and total fluoroscopy time.
RESULTS: All procedures were successful. No major complications. Minor post procedural headache in one injection resolved spontaneously on day 2 post procedure.
Median procedural flouroscopic time 2.4 min, Median air kerma 29 mGy.
CONCLUSION: Flouroscopic guidance alone is a safe and effective method for gaining transforaminal intrathecal access in children with spinal abnormalities and hardware precluding the use of standard techniques. CT guidance is not absolutely necessary for transforaminal thecal access.
