Image-guided intrathecal baclofen pump catheter implantation: a technical note and case series

OBJECTIVE Medically refractory spasticity and dystonia are often alleviated with intrathecal baclofen (ITB) administration through an indwelling catheter inserted in the lumbar spine. In patients with cerebral palsy, however, there is a high incidence of concomitant neuromuscular scoliosis. ITB placement may be technically challenging in those who have severe spinal deformity or who have undergone prior instrumented thoracolumbar fusion. Although prior reports have described drilling through the lumbar fusion mass with a high-speed bur, as well as IT catheter implantation at the foramen magnum or cervical spine, these approaches have notable limitations. To the authors' knowledge, this is the first report of ITB placement using cone beam CT (CBCT) image guidance to facilitate percutaneous IT catheterization. METHODS Data were prospectively collected on patients treated between November 2012 and June 2014. In the interventional radiology suite, general anesthesia was induced and the patient was positioned prone. Imaging was performed to identify the optimal trajectory. Percutaneous puncture was performed at an entry site with image-guided placement of a sheathed needle. CBCT provided real-time 2D projections and 3D reconstructions for detailed volumetric imaging. A biopsy drill was passed through the sheath, and subsequently a Tuohy needle was advanced intrathecally. The catheter was threaded cephalad under fluoroscopic visualization. After tip localization and CSF flow were confirmed, the stylet was replaced, the external catheter tubing was wrapped sterilely in a dressing, and the patient was transported to the operating room. After lateral decubitus positioning of the patient, the IT catheter was exposed and connected to the distal abdominal tubing with typical pump placement. RESULTS Of 15 patients with Gross Motor Function Classification System Levels IV and V cerebral palsy and instrumented thoracolumbar fusion, 8 had predominantly spasticity, and 7 had mixed spasticity and dystonia. The mean age of patients was 20.1 years (range 13-27 years). Nine patients underwent initial catheter and pump placement, and 6 underwent catheter replacement. The procedure was technically successful, with accurate spinal catheter placement in all patients. The median hospital stay was 4 days (IQR 3-5 days). One patient had an early postoperative urinary tract infection. With a mean follow-up of 25.8 months (median 26, range 18-38 months), no CSF leakage or catheter failure occurred. One late infection due to Pseudomonas aeruginosa (requiring pump explantation) occurred at 4 months, probably secondary to recurrent urinary tract infections. CONCLUSIONS Image-guided CBCT navigation resulted in accurate percutaneous placement of the IT catheter for ITB pumps in patients with prior instrumented thoracolumbar fusion. The multimodality approach is an alternate technique that may be used for IT catheter insertion in patients with complex lumbar spine anatomy, extending the potential to provide safe, durable ITB therapy in this population.