Purpose or Case Report: Patients with Spinal Muscular Atrophy (SMA) may have scoliosis requiring spinal hardware for spinal fixation. The scoliosis in addition to the spinal hardware makes intrathecal access difficult with conventional approaches. With recent FDA approval of nusinersen (SpinrazaÒ) for SMA, intrathecal access is required for administration of this meditation. We describe our experience in these patients using a variety of lumbar puncture approaches (intra-spinous process, trans-pedicle, and trans-foraminal) utilizing conventional fluoroscopy, cone-beam CT (CBCT) with fluoroscopy overlay and/or conventional CT with CT fluoroscopy. Approach to the type of access and image guidance is based on the presence of spinal hardware and degree of scoliosis and spinal fusion.
Methods & Materials: An IRB approved retrospective review was performed of our data base of SMA patients having such injection. The technique, technical success and complications were reviewed.
Results: To date, there have been 25 patients receiving 73 procedures. 15 of the 25 patients had spinal hardware (10 patients with conventional rods; 5 with expandable rods). 15 procedures (6 patients) all with conventional spinal rods and some degree of spinal fusion required either CT or CBCT. The remainder of the procedures were performed with conventional fluoroscopy. 14 procedures (5 patients with conventional spinal rods), required trans-foraminal approach. After initial procedures were performed with CBCT or CT guidance, several patients had subsequent procedure performed with conventional fluoroscopy utilizing a trans-foraminal approach.

71 of the 73 procedures (97%) were technically successful with intrathecal injection. The two non-successful procedures were initially performed with conventional fluoroscopy and subsequently performed with technical success using CT (one with trans-foraminal approach). One complication of a CSF leak and one complication of persistent back pain 5 days post procedure were identified. Both complications were self-limited and resolved.
Conclusions: In SMA patients with complex scoliosis or extensive spinal hardware with fusion, successful intrathecal can be achieved utilizing a trans-formainal or trans-pedicle approach. Some patients may require CBCT with fluoroscopy overlay or conventional CT with CT fluoroscopy and laser guide.