Ultrasound‐guided transforaminal approach for nusinersen delivery in adult spinal muscle atrophy patients with challenging access

Abstract Introduction/Aims Previous papers on ultrasound (US)‐guided delivery of nusinersen in patients with spinal muscle atrophy (SMA) described good results with translaminar approach. However, this approach is not possible in patients with spinal fusion and no visible interlaminar space on pre‐procedural computed tomography (CT). US‐guided transforaminal nusinersen delivery is a potential option that warrants investigation. Methods Twenty adult SMA patients with challenging access were treated in our institution under cone beam CT (CBCT) guidance. The patients were already in the maintenance phase of the dosing protocol and were prospectively evaluated for US‐guided transforaminal approach. After they completed one injection via US‐guided transforaminal approach, success and safety of the approach were analyzed. Patients shared their experience on US‐guided in comparison to CBCT‐guided injections. Results US‐guided transforaminal puncture was possible in 14 (70.0%) patients, although 2 of them required needle repositioning under fluoroscopy due to inadvertent access of a prominent vein. US‐guided transforaminal approach was therefore successful in 60% of patients. Mild adverse events were recorded in four patients. The survey on patients' experience showed that seven reported no difference in the two approaches, six preferred the US‐guided procedure, and one preferred the CBCT‐guided procedure. Discussion US‐guided transforaminal lumbar approach is an effective and safe method of intrathecal nusinersen delivery in adult SMA patients with challenging spinal access and could be considered the first option in appropriately selected adult SMA patients requiring transforaminal nusinersen delivery.